Playpens are space for safely taking care of young babies and there are lots of different designs of playpens available in the market. Some of the conventional playpens have a non-foldaway structure and thus occupying a great space when not in use. A foldaway playpen frame structure was developed to overcome the space problem. Such a foldaway playpen structure provides a saving in storage space when the playpen is not in use. Examples are Taiwan Patent Application Nos. 81208167 and 81208161. Both applications are filed under the name of the applicant of the present invention.
Conventional foldaway playpen frame structures comprise a collapsible top rail structure under which legs are pivotally secured at their upper ends. In the playpen of Taiwan Patent Application No. 81208167, there is provided a reinforcement structure pivotally mounted between the legs substantially at the lower ends thereof to more securely hold the legs in position. The problem of the reinforcement structure disclosed in the prior art Taiwanese patent is that once the reinforcement structure is accidently hit or struck, a sudden, undesired collapse of the playpen frame may occur. This may hurt the baby sitting therein.
In Taiwan Patent Application No. 81208161, a joint for connecting two bars in a collapsible manner to form a top rail is disclosed. The joint has a complicated and inefficient structure so that when folded, the playpen still occupies a large space. Further, the prior art joint is expensive due to the complication thereof.
A co-pending US Patent Application Ser. No. 08/032,133, filed on Mar. 16, 1993, still pending, under the name of the applicant of the present invention, discloses a foldaway playpen frame structure which although intended to overcome the previous problems, has a joint structure which is not very reliable.
It is therefore desirable to provide a foldaway playpen frame structure which overcomes the deficiencies of the conventional playpen structures.